As electronic technology and communication network have been continuously developed, hardware, software, and features of video conferencing are notably enhanced. The current video conferencing allows multiple users to be connected with each other at anytime through electronic devices such as computers, smart phones, and tabular computers. While the users are voice calling each other, they would be able to see others' motion through screens, and a realistic telepresence experience in communication would be thereby enhanced. Accordingly, video conferencing has been extensively used in business communication so that enterprises are able to perform cross-regional communication internally and externally.
In general, to minimize data amount for video and audio data transmission, video and audio data would be separated, encoded and compressed before transmitted to a remote device. Since the sizes of a video packet and an audio packet are different, their transmission times would also be different. Accordingly, after a receiving device receives the packets, the video data and the audio data could not be synchronizedly played, and thus the quality and efficiency of the communication would be affected.